Sol-gel chemistry for Ba2+ sensors to allow oil production engineered nanometrically

Work on the development of a Ba2 +-sensitive sol–gel based optical fiber (OF) for use in oil wells is described. The optical fiber (OF) has on its surface a Ba2 + chelating ligand (L) immobilized at a 2–16 wt% loading immobilized in a porous SiO2 sol–gel host. The authors report sol–gel routes to these SiO2 and L/SiO2 nanocomposites and describe their characterization by XPS, fluorescence, NMR, UV-vis and BET methods. They also report on the sol–gel coating and its selectivity to Ba2 +(aq).